Scattered/transmitted light information system

摘要

In an information gathering system especially suited to the monitoring of vegetable products in sorting apparatus, a light beam (23) is directed by a scanning source such as a laser (11) at the surface of an object (2) such as a tomato moving in the direction x-x through a scanning zone. The scanning operation is conducted in the y-y direction. Directly reflected light returned from the surface of the object (2) along a path (17) extending from light beam target region (12) is sensed by a line detector (14), which provides an output signal indicative of the level, of the directly reflected light. Light entering the material of the organic product (2) is subjected to a light scattering or diffusing process within the material of the product, so that at least a region (13) of the surface of the product (12) surrounding the target zone (12) of light beam (23) becomes lit-up or illuminated from within. Further photosensitive line detectors (15) and (16) located one to each side of reflected light detector (14) monitor the levels of light emanating from this illuminated zone (13) surrounding light beam target zone (12) and reaching the detectors (15) and (16) along paths (18) and (19) respectively. Comparison of the relative levels of the directly reflected light and emanating light signals enables information to be derived as to surface and sub-surface defects on or in the product (2). The use of suitable logic circuitry enables rejection of defective product in response to the information provided by the light signals.